Pinto beans as a course of bioavailable selenium to support bone structure in mice

Authors: Cao, Jay; Gregoire, Brian; Zeng, Huawei

Submitted to: Journal of Bone and Mineral Research
Publication Type: Abstract Only
Publication Acceptance Date: 5/30/2010
Publication Date: 12/10/2010
Citation: Cao, J.J., Gregoire, B.R., Zeng, H. 2010. Pinto beans as a course of bioavailable selenium to support bone structure in mice [abstract]. Journal of Bone and Mineral Research. 25(Supplement 1).

Interpretive Summary:

Technical Abstract: Selenium (Se) is an essential trace mineral for animals and humans. The deficiency of Se has been linked to increased oxidative stress with increased levels of reactive oxygen species (ROS). Oxidative stress and ROS have been shown to stimulate bone resorption and osteoclast activity. Selenium, a chemical component of selenoproteins (such as glutathione peroxidases and thioredoxin reductase), plays a major role in cellular redox status and may have beneficial effects on bone health. The objective of the study was to determine whether Se deficiency affects bone microarchitecture and whether Se from pinto beans (SeB) is bioavailable as compared to that of Se in the form of selenomethionine (SeM) in supporting normal bone development in a mouse model. Thirty-three male C57BL/6J mice, 18-wk-old, were assigned randomly to three groups. Mice were fed either purified Se-deficient diet (SeD) containing ~0.005 ppm Se, or diets containing ~0.1 ppm Se in the form of SeM or SeB for four months. Selenium concentration in liver and glutathione peroxidase activity in red blood cells were higher in mice fed SeM or SeB diet than those fed SeD diet (P < 0.0001). Mice fed SeM or SeB diet had higher femoral trabecular bone volume/total volume and trabecular number and lower trabecular separation than mice fed SeD diet. Selenium deficiency did not affect any mid-shaft cortical bone parameters of the femur (P > 0.05). Interestingly, mice fed SeB diet had higher liver Se concentration (P < 0.05) but similar glutathione peroxidase activity in red blood cells as compared to mice fed SeM diet. There were no significant differences in bone structural parameters between SeM and SeB groups (P > 0.05). Taken together, this study demonstrates that Se plays a critical role in supporting bone structure and Se from pinto beans is equally bioavailable to support normal bone development in mice as compared to Se in the form of selenomethionine.